package nowcoder.day_48.day9;

import java.io.IOException;
import java.util.Scanner;

public class Num2 {
    public static void main(String[] args) throws IOException {
        Scanner in = new Scanner(System.in);
        int m = in.nextInt();
        int n = in.nextInt();
        int [][]dp = new int[m + 1][n + 1];
        for (int i = 0; i <= m; i++) {
            dp[i][0] = 1;
        }
        for (int i = 0; i <= n; i++) {
            dp[0][i] = 1;
        }
        for (int i = 1; i <= m; i++) {
            for (int j = 1; j <= n ; j++) {
                dp[i][j] = dp[i][j - 1] + dp[i - 1][j];
            }
        }
        System.out.println(dp[m][n]);
    }
}
